Audi Q8 vs GMC Terrain: Specs Compared

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the GMC Terrain burns about $2,200 of fuel annually against $3,800 for the Audi Q8. That $1,600 yearly gap compounds to roughly $8,000 over five years and $12,800 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.

City and highway economy: the GMC Terrain leads in both cycles — 28 mpg city and 39 mpg highway against 18 and 23 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the Audi Q8 is recorded with 1 distinct engine configuration (SIDI; Mild Hybrid), the GMC Terrain with 3 (SIDI, 1.6, SIDI; FFV). Across 9 recorded Audi Q8 configurations and 47 for the GMC Terrain, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.

Drivetrain and class: the Audi Q8 is offered with All-Wheel Drive, the GMC Terrain with All-Wheel Drive, Front-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Standard Sport Utility Vehicle 4WD and Small Sport Utility Vehicle 2WD respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the GMC Terrain emits 316 g/mile of CO2 versus 439 g/mile for the Audi Q8. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.